HEMPSTEAD, N.Y. (CBSNewYork) — On the first day of the new semester at Hofstra University, students were alerted about a home invasion and robbery that happened on Monday night at an off-campus house filled with sorority sisters.

CBS2’s Carolyn Gusoff spoke to some of the victims on Tuesday.

“You always know there’s a chance of it happening, but you never think it’s going to happen to you. It was so scary,” Jamie Rollo said.

Web Extra: Expert Weighs In On Off-Campus Home Invasion Near Hofstra 

They were terrifying moments for Rollo, her boyfriend and five sorority sisters at her house on Fairview Boulevard, just blocks from campus. She said she was asleep at around 11:30 p.m. when a masked man brandishing a gun walked in through an unlocked side door.

“He pointed it at us originally and said, ‘This is what is happening: You’re going to give me everything,'” Rollo said. “He told me to shut up, stop screaming. ‘I need all your money. I know you have it.'”

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Rollo said she told the man she had nothing of value, but handed over her laptop and passwords, as he demanded.

“Then he had us lay down on our stomachs and walked out of the room,” Rollo said.

“I was in the basement, so I heard footsteps. What are those footsteps? Who is walking around upstairs?” victim Ashley Petrillo added.

Nassau police said it was a crime of opportunity — a door left unlocked.

“We haven’t gotten blinds on this window yet,” Rollo said. “I don’t know if he was watching us all week and getting our patterns. To me, it looked like he came fresh off the street and was looking for that unlocked door.”

Another problem seemed to be a lack of illumination in parts of the house, which is a common mistake, said risk management expert Anthony Roman, who warns that students living on their own need to do more to protect themselves.

Roman suggests:

— Always locking doors and windows
— demanding the landlord install outside lights
— Install shades
— Assigning a non-drinking door monitor during parties
— Setting up phones for one-push calling to 911 and police resources

“They should unite form a security fund, each contributing a small amount to have mobile panic alarm on each floor, security perimeter systems for the windows, the doors … that would go long way as a deterrent,” Roman said.

While it was five years ago, the friendly fire shooting death of a Hostra student is still a tragic reminder of how volatile armed home invasions can be.

On Tuesday, the university released a statement sent out an alert reminding students of basic safety.

“Hofstra university is fully cooperating with local law enforcement, which is investigating the off-campus incident,” the statement read. “We are grateful that no one was physically injured and have offered counseling and other assistance to the student residents of the home. The university sent out a safety alert shortly after being notified of the off-campus incident that included basic safety information for students living on- and off-campus.”

“Last year, I had something taken, too, so it’s a bit of a wake-up call,” one student said.

The girls could only provide a vague description of the perpetrator — a black man in his early 20, around 5-foot-10 with a muscular build and a bandana hiding his face. He is still at large.